Lesson 21: Backward Counting
Lesson Objectives
- Count backward within 10
- Recognize patterns in number sequences
- Identify numbers out of order or missing
- Locate and compare numbers on number lines
Materials
- Extend Workbook (Page 21)
- Counters or manipulatives
- TouchMath’s number line or other number line 0-10
- TouchMath’s Number Cards (optional)
Step 1: Warm Up (5 min)
Ask the students share an experience in which they counted backward at home (e.g., watching the timer on the microwave, computer, or game activity count down). Start an ongoing class list of experiences where numbers were counted backward (e.g. timers on crosswalks, sports events, etc.) and continue to add to the list each day. Optional: Choose one of the following activities for a warm-up: 1) direct the students to draw a picture of their family in an elevator and write a story about the count down of the floors; 2) Play a Freeze Game, let them run around until you say freeze. Give them a number (change it up to build the skills and make it fun), and have them count backwards; 3) Play hide and seek and count backwards from 10 before saying “Ready or not, here I come!”
Step 2: Vocab Review (5 min)
Introduce new vocabulary: count backward, sequence, pairs, andeven numbers.
Step 3: Model (5 min)
Practice counting backward from any numbers and stopping at any number. For example, when counting backward from 16, stop at 10, 8, 7, etc. Call around the room or in your groups, and ask students to count backward from any given number (10 and below). If students are older, you can start on a higher number. Discuss what a “pair” means, giving real-life examples: eyes, ears, hands, etc. Ask students to come up with other “pairs” on their own. Explain that pairs are two things that are the same, when we think about a pair of eyes, it is two eyes. When we think of a pair of shoes and a pair of socks, explain that it means two shoes and two socks. Explain that since pairs are two things that are the same, all pairs are even numbers. Show a number line 0-10 or draw one on the white board: Draw tick marks for the even numbers. Start at 0, and skip count by 2 and end on 10. Explain that those are pairs, and to think of them as doubles. Say: “What two equal addends make 2? Yes, 1 + 1. What two equal addends make 4? Yes, 2 + 2. How about 6? 8? Whenever you have two equal addends, the result is an even number. The sums will always have 0, 2, 4, 6, or 8 in the ones place.
Step 4: Guided Practice (5 min)
Have students work together in partners or pairs and practice counting backward from a number within 5, then within 10. After practicing this, have studnets count forward from any given number up to 20. Then practice with pairs and even numbers. Explain to students that another key is that a pair is two items that are typically used together, two partners. Think about a married couple, twins, dance partners (e.g., pairs of ice skaters), tires on a bicycle, names of businesses (e.g., Abercrombie and Fitch, Barnes and Noble), and many more. Can you think of pairs or partners that you see every day? Ask students to make a list and write down all class ideas on the board. Show an open number line and practice finding a number on the number line and placing a dot on the line to represent that number. Then, show loops going backward as you count backward on the number line and place a dot on the number “before” it or wherever you want to stop.
Step 5: Student Practice (5 min)
Go to Student Workbook Page (21). Read the directions at the top of the page. Tell students they will first find the number mentioned in the question (9) and make a dot on the line. Then, have students loop backwards one time to get to the number before it (8). Write the number on the line provided. Repeat for the next problem. Next, go to the number patterns and fill in the missing numbers in the patterns. Tell students to pay attention if it is going backward or forward before filling in the missing number. Lastly, ask students to solve the pattern of the domino blocks with two dots. Tell them to count the number of dominos on the top and write the number next to it (4), and to continue doing that until they get to the box. Fill in the next number in the sequence.
Step 6: Wrap Up (5 min)
To wrap up the lesson, review the learning objectives and core vocabulary words again and ask your students about their experience. Circle back to those real-life connections and experiences.
